According to Apple, the software update "includes bug fixes, increased stability and performance improvements for iPad 2 and iPhone 4s".

Technically, these devices supported iOS 8, but they soon suffered performance issues, according to several media reports.

With the iOS 8.1.1 release here, we've also tested the latest firmware update on the Apple iPad Air. And, thus far, there have been no major issues. Depending on the device and model, the software update size will vary. The size weighs in between 65MB and 364MB.